Imaging systems used for monitoring an area typically include mechanical components for moving the imaging device, such as a camera, to direct the photodetectors associated with the camera towards an area of interest. In order to search over a given field-of-regard, the optical system must either be gimbaled or have its field of view otherwise directable.
Conventional beam-steering arrangements for missiles include an optically transmissive dome and an optical arrangement behind the dome, and a gimbal that rotates the entire optical arrangement. A disadvantage of conventional gimbaled optical arrangements for certain applications is that conventional gimbaled optical arrangements need ample amounts of sway space in order to sweep through a field-of-regard and therefore can impose expensive packaging constraints on other system attributes. Other disadvantages of gimbaled optical arrangements include significant weight and cost, as well as poor performance.
For example, conventional electro-optical missile technologies employ a dome-gimbal configuration where the optical system is placed in a gimbal behind an electro-optically transmissive dome. The domes are typically rotationally symmetric, placed at the tip of the missile, are spherical or conformal in shape, and are selected with aerodynamic performance as the primary design consideration.
In some applications, it is not practical to move the lens assembly and camera. For those instances, it would be desirable for the optical system to provide pan and tilt functionality without requiring physical movement of the lens assembly and camera.